1. Field of the Invention
The present invention relates to a video tape editing apparatus, and in particular, to a video tape editing apparatus which performs a signal insertion editing operation on a video tape on which audio signals are recorded on the same track(s) together with video signals in accordance with a helical scanning system.
2. Description of the Prior Art
For the insertion editing operation for recording new video signals, with audio signals if necessary, on a portion of video tape on which signals have already been recorded, it is necessary to record new video signals with proper matching established with respect to the track(s), on which video signals are already recorded, in order to not disturb the synchronization for regenerating the video signals.
In a video tape recorder adopting a conventional system in which audio signals are recorded on a track different from a video track, a full-erase head need not be utilized for the insertion of new video signals and consequently, only video signals previously recorded on the video track can be replaced with, or overwritten by, new video signals by a video head while retaining the audio signals recorded on the audio track.
However, in a system in which audio and video tracking signals are recorded on a video track, for example, by superimposing these signals with video signals, the audio signals previously recorded on the track will be erased if the new video signals are recorded on the track.
For a motion picture playback operation, it may be often required to insert necessary related images, such as an explanation about an image and a title thereof, into a recorded scene. Since such related images are closely associated with the environment of the recorded scene, a sudden interruption of the voice and sound due to the insertion, which have been continuously reproduced while playing back the recorded signals, would be disconcerting to the viewer. Even if another audio sound is inserted after the interruption of the audio signals due to the insert operation, an unnatural impression cannot be suppressed. Therefore, if other audio sound should be inserted, it is required for the insertion to retain the voice and sound previously recorded as much as possible, for example, by mixing it with the signals of other audio sound to be inserted with the previously recorded audio signals.